Fluid-actuated mechanisms for carrying out mechanical work are known in the art and have been described in a number of patents. U.S. Pat. No. 2,518,990 describes a fluid-actuated hose reel in a lawn sprinkler. U.S. Pat. No. 2,989,605 describes a water-powered retractable shower head. More recently, U.S. Pat. No. 5,741,188 discloses a ride-on toy or a garden tool which includes a stationary element, a movable element connected thereto, water pressure operating means for moving the movable element with respect to the stationary element, a water inlet and a water outlet, and a valve for controlling the flow of the water through the device.
European Application 136414 A2 discloses a water flow operated device for winding and/or unwinding a layer of flexible material which comprises a stationary element, a spool having a central axis, said spool being rotatable about a central axis when engaged with the stationary element; and a water flow-operated mechanism engaged by said stationary element for controllably rotating said spool.
Of particular interest to the present invention is Eliot U.S. Pat. No. 1,954,408 which discloses a fluid-driven engine, comprising: a drive unit connectable to a source of pressurized fluid and including a piston movable within a cylinder; a valve assembly controlling the introduction of pressurized fluid into the cylinder, and the discharge of spent fluid therefrom for driving the piston with respect to the cylinder; and a rotatable drive shaft including a crank arm coupled to the drive unit for rotating the drive shaft about a rotary axis; the piston projecting through one end of the cylinder and being pivotally coupled to the crank arm for rotating the drive shaft during forward and return strokes of the piston with respect to the cylinder; the opposite end of the cylinder being pivotally mounted to the valve assembly so as to oscillate with the piston between opposite sides of the drive shaft rotary axis during the forward and return strokes of the piston; the opposite end of the cylinder being formed with a port through which pressurized fluid is introduced and spent fluid is discharged as controlled by the valve assembly during the oscillations of the cylinder and piston.